XRF (X-ray fluorescence) testing points an X-ray beam at a piece of jewellery and reads the energy the metals give back, which shows which elements are present and in roughly what amounts. It takes seconds, does not damage the piece, and is widely used to screen jewellery for lead and cadmium and to measure plating thickness.
It does not measure how much nickel is released onto skin, which is what EU and UK rules limit. That needs a separate chemical test.
What XRF is good for
- Screening for lead, cadmium and other heavy metals in metal parts and coatings.
- Measuring the thickness of gold, rhodium or silver plating, usually in microns.
- Confirming the base metal, for example brass versus a zinc alloy.
- Checking that production pieces match the sample that passed a full lab test.
- Sorting suspect lots quickly, before you spend money on full testing.
Where XRF falls short
XRF reads the surface and a shallow depth below it. On plated jewellery, the reading mixes the plating and the base metal, so a thin layer of gold over a leaded alloy can give a misleading result. Small, curved or mixed-material parts are also hard to read accurately.
Nickel release is measured with the EN 1811 test, where the piece sits in artificial sweat for a week. XRF can show that nickel is present, but not whether the release is above the limit. For certificates such as a US Children's Product Certificate, the lab must use the test methods the CPSC accepts for each material. XRF is accepted for some materials and not others, so ask the lab.
Handheld units versus lab instruments
Handheld XRF guns are common in inspection work and in larger factories. They are excellent for screening but less precise on small jewellery parts. Benchtop instruments in labs give better accuracy and are standard for plating thickness. A sensible programme uses handheld XRF during production and inspection, and full lab tests on the approved sample and on production lots.
What this means for a buyer
Use XRF to catch problems early and cheaply, and full lab tests to prove compliance. Ask makers to share XRF plating readings on samples, and confirm them yourself before you approve. If plating thickness is part of your quality standard, write it into your purchase order with a tolerance.
Creston & Co works for buyers only, for a fixed fee agreed in writing. We check plating and finish on site, have samples tested at NABL-accredited labs and compare production against the approved sample before packing. Start with a free sourcing review.